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1da177e4
LT
1/*
2 * fs/cifs/cifsglob.h
3 *
5815449d 4 * Copyright (C) International Business Machines Corp., 2002,2006
1da177e4
LT
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 */
18#include <linux/in.h>
19#include <linux/in6.h>
20#include "cifs_fs_sb.h"
21/*
22 * The sizes of various internal tables and strings
23 */
24#define MAX_UID_INFO 16
25#define MAX_SES_INFO 2
26#define MAX_TCON_INFO 4
27
28#define MAX_TREE_SIZE 2 + MAX_SERVER_SIZE + 1 + MAX_SHARE_SIZE + 1
29#define MAX_SERVER_SIZE 15
30#define MAX_SHARE_SIZE 64 /* used to be 20 - this should still be enough */
31#define MAX_USERNAME_SIZE 32 /* 32 is to allow for 15 char names + null
32 termination then *2 for unicode versions */
33#define MAX_PASSWORD_SIZE 16
34
35#define CIFS_MIN_RCV_POOL 4
36
37/*
38 * MAX_REQ is the maximum number of requests that WE will send
39 * on one socket concurently. It also matches the most common
40 * value of max multiplex returned by servers. We may
41 * eventually want to use the negotiated value (in case
42 * future servers can handle more) when we are more confident that
43 * we will not have problems oveloading the socket with pending
44 * write data.
45 */
46#define CIFS_MAX_REQ 50
47
48#define SERVER_NAME_LENGTH 15
49#define SERVER_NAME_LEN_WITH_NULL (SERVER_NAME_LENGTH + 1)
50
51/* used to define string lengths for reversing unicode strings */
52/* (256+1)*2 = 514 */
53/* (max path length + 1 for null) * 2 for unicode */
54#define MAX_NAME 514
55
56#include "cifspdu.h"
57
58#ifndef FALSE
59#define FALSE 0
60#endif
61
62#ifndef TRUE
63#define TRUE 1
64#endif
65
66#ifndef XATTR_DOS_ATTRIB
67#define XATTR_DOS_ATTRIB "user.DOSATTRIB"
68#endif
69
70/*
71 * This information is kept on every Server we know about.
72 *
73 * Some things to note:
74 *
75 */
76#define SERVER_NAME_LEN_WITH_NULL (SERVER_NAME_LENGTH + 1)
77
78/*
79 * CIFS vfs client Status information (based on what we know.)
80 */
81
82 /* associated with each tcp and smb session */
83enum statusEnum {
84 CifsNew = 0,
85 CifsGood,
86 CifsExiting,
87 CifsNeedReconnect
88};
89
90enum securityEnum {
3979877e
SF
91 LANMAN = 0, /* Legacy LANMAN auth */
92 NTLM, /* Legacy NTLM012 auth with NTLM hash */
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93 NTLMv2, /* Legacy NTLM auth with NTLMv2 hash */
94 RawNTLMSSP, /* NTLMSSP without SPNEGO */
95 NTLMSSP, /* NTLMSSP via SPNEGO */
96 Kerberos /* Kerberos via SPNEGO */
97};
98
99enum protocolEnum {
100 IPV4 = 0,
101 IPV6,
102 SCTP
103 /* Netbios frames protocol not supported at this time */
104};
105
106/*
107 *****************************************************************
108 * Except the CIFS PDUs themselves all the
109 * globally interesting structs should go here
110 *****************************************************************
111 */
112
113struct TCP_Server_Info {
a10faeb2
SF
114 /* 15 character server name + 0x20 16th byte indicating type = srv */
115 char server_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
d3485d37 116 char unicode_server_Name[SERVER_NAME_LEN_WITH_NULL * 2];
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117 struct socket *ssocket;
118 union {
119 struct sockaddr_in sockAddr;
120 struct sockaddr_in6 sockAddr6;
121 } addr;
122 wait_queue_head_t response_q;
123 wait_queue_head_t request_q; /* if more than maxmpx to srvr must block*/
124 struct list_head pending_mid_q;
125 void *Server_NlsInfo; /* BB - placeholder for future NLS info */
126 unsigned short server_codepage; /* codepage for the server */
131afd0b 127 unsigned long ip_address; /* IP addr for the server if known */
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128 enum protocolEnum protocolType;
129 char versionMajor;
130 char versionMinor;
131 unsigned svlocal:1; /* local server or remote */
132 atomic_t socketUseCount; /* number of open cifs sessions on socket */
133 atomic_t inFlight; /* number of requests on the wire to server */
131afd0b
SF
134#ifdef CONFIG_CIFS_STATS2
135 atomic_t inSend; /* requests trying to send */
136 atomic_t num_waiters; /* blocked waiting to get in sendrecv */
137#endif
1da177e4
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138 enum statusEnum tcpStatus; /* what we think the status is */
139 struct semaphore tcpSem;
140 struct task_struct *tsk;
141 char server_GUID[16];
142 char secMode;
143 enum securityEnum secType;
144 unsigned int maxReq; /* Clients should submit no more */
145 /* than maxReq distinct unanswered SMBs to the server when using */
146 /* multiplexed reads or writes */
147 unsigned int maxBuf; /* maxBuf specifies the maximum */
148 /* message size the server can send or receive for non-raw SMBs */
149 unsigned int maxRw; /* maxRw specifies the maximum */
150 /* message size the server can send or receive for */
151 /* SMB_COM_WRITE_RAW or SMB_COM_READ_RAW. */
152 char sessid[4]; /* unique token id for this session */
153 /* (returned on Negotiate */
154 int capabilities; /* allow selective disabling of caps by smb sess */
155 __u16 timeZone;
1982c344 156 __u16 CurrentMid; /* multiplex id - rotating counter */
1da177e4 157 char cryptKey[CIFS_CRYPTO_KEY_SIZE];
a10faeb2
SF
158 /* 16th byte of RFC1001 workstation name is always null */
159 char workstation_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
ad009ac9 160 __u32 sequence_number; /* needed for CIFS PDU signature */
7c7b25bc 161 char mac_signing_key[CIFS_SESS_KEY_SIZE + 16];
1da177e4
LT
162};
163
164/*
165 * The following is our shortcut to user information. We surface the uid,
166 * and name. We always get the password on the fly in case it
167 * has changed. We also hang a list of sessions owned by this user off here.
168 */
169struct cifsUidInfo {
170 struct list_head userList;
171 struct list_head sessionList; /* SMB sessions for this user */
172 uid_t linux_uid;
173 char user[MAX_USERNAME_SIZE + 1]; /* ascii name of user */
174 /* BB may need ptr or callback for PAM or WinBind info */
175};
176
177/*
178 * Session structure. One of these for each uid session with a particular host
179 */
180struct cifsSesInfo {
181 struct list_head cifsSessionList;
182 struct semaphore sesSem;
3979877e 183#if 0
1da177e4 184 struct cifsUidInfo *uidInfo; /* pointer to user info */
3979877e 185#endif
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LT
186 struct TCP_Server_Info *server; /* pointer to server info */
187 atomic_t inUse; /* # of mounts (tree connections) on this ses */
188 enum statusEnum status;
750d1151 189 unsigned overrideSecFlg; /* if non-zero override global sec flags */
1da177e4
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190 __u16 ipc_tid; /* special tid for connection to IPC share */
191 __u16 flags;
ad009ac9
SF
192 char *serverOS; /* name of operating system underlying server */
193 char *serverNOS; /* name of network operating system of server */
1da177e4
LT
194 char *serverDomain; /* security realm of server */
195 int Suid; /* remote smb uid */
196 uid_t linux_uid; /* local Linux uid */
197 int capabilities;
ad009ac9
SF
198 char serverName[SERVER_NAME_LEN_WITH_NULL * 2]; /* BB make bigger for
199 TCP names - will ipv6 and sctp addresses fit? */
1da177e4 200 char userName[MAX_USERNAME_SIZE + 1];
3979877e 201 char * domainName;
1da177e4
LT
202 char * password;
203};
204/* session flags */
205#define CIFS_SES_NT4 1
206
207/*
208 * there is one of these for each connection to a resource on a particular
209 * session
210 */
211struct cifsTconInfo {
212 struct list_head cifsConnectionList;
213 struct list_head openFileList;
214 struct semaphore tconSem;
215 struct cifsSesInfo *ses; /* pointer to session associated with */
254e55ed 216 char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
1da177e4
LT
217 char *nativeFileSystem;
218 __u16 tid; /* The 2 byte tree id */
219 __u16 Flags; /* optional support bits */
220 enum statusEnum tidStatus;
254e55ed 221 atomic_t useCount; /* how many explicit/implicit mounts to share */
1da177e4
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222#ifdef CONFIG_CIFS_STATS
223 atomic_t num_smbs_sent;
224 atomic_t num_writes;
225 atomic_t num_reads;
226 atomic_t num_oplock_brks;
227 atomic_t num_opens;
a5a2b489 228 atomic_t num_closes;
1da177e4
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229 atomic_t num_deletes;
230 atomic_t num_mkdirs;
231 atomic_t num_rmdirs;
232 atomic_t num_renames;
233 atomic_t num_t2renames;
dfb7533b
SF
234 atomic_t num_ffirst;
235 atomic_t num_fnext;
236 atomic_t num_fclose;
a5a2b489
SF
237 atomic_t num_hardlinks;
238 atomic_t num_symlinks;
239 atomic_t num_locks;
0a4b92c0
SF
240 atomic_t num_acl_get;
241 atomic_t num_acl_set;
a5a2b489
SF
242#ifdef CONFIG_CIFS_STATS2
243 unsigned long long time_writes;
244 unsigned long long time_reads;
245 unsigned long long time_opens;
246 unsigned long long time_deletes;
247 unsigned long long time_closes;
248 unsigned long long time_mkdirs;
249 unsigned long long time_rmdirs;
250 unsigned long long time_renames;
251 unsigned long long time_t2renames;
252 unsigned long long time_ffirst;
253 unsigned long long time_fnext;
254 unsigned long long time_fclose;
255#endif /* CONFIG_CIFS_STATS2 */
1da177e4
LT
256 __u64 bytes_read;
257 __u64 bytes_written;
258 spinlock_t stat_lock;
a5a2b489 259#endif /* CONFIG_CIFS_STATS */
1da177e4 260 FILE_SYSTEM_DEVICE_INFO fsDevInfo;
254e55ed 261 FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo; /* ok if fs name truncated */
1da177e4
LT
262 FILE_SYSTEM_UNIX_INFO fsUnixInfo;
263 unsigned retry:1;
d3485d37 264 unsigned nocase:1;
1da177e4
LT
265 /* BB add field for back pointer to sb struct? */
266};
267
268/*
269 * This info hangs off the cifsFileInfo structure. This is used to track
270 * byte stream locks on the file
271 */
272struct cifsLockInfo {
273 struct cifsLockInfo *next;
274 int start;
275 int length;
276 int type;
277};
278
279/*
280 * One of these for each open instance of a file
281 */
282struct cifs_search_info {
283 loff_t index_of_last_entry;
284 __u16 entries_in_buffer;
285 __u16 info_level;
286 __u32 resume_key;
287 char * ntwrk_buf_start;
288 char * srch_entries_start;
289 char * presume_name;
290 unsigned int resume_name_len;
291 unsigned endOfSearch:1;
292 unsigned emptyDir:1;
293 unsigned unicode:1;
ec637e3f 294 unsigned smallBuf:1; /* so we know which buf_release function to call */
1da177e4
LT
295};
296
297struct cifsFileInfo {
298 struct list_head tlist; /* pointer to next fid owned by tcon */
299 struct list_head flist; /* next fid (file instance) for this inode */
300 unsigned int uid; /* allows finding which FileInfo structure */
301 __u32 pid; /* process id who opened file */
302 __u16 netfid; /* file id from remote */
303 /* BB add lock scope info here if needed */ ;
304 /* lock scope id (0 if none) */
305 struct file * pfile; /* needed for writepage */
306 struct inode * pInode; /* needed for oplock break */
307 unsigned closePend:1; /* file is marked to close */
308 unsigned invalidHandle:1; /* file closed via session abend */
23e7dd7d 309 atomic_t wrtPending; /* handle in use - defer close */
1da177e4
LT
310 struct semaphore fh_sem; /* prevents reopen race after dead ses*/
311 char * search_resume_name; /* BB removeme BB */
1da177e4
LT
312 struct cifs_search_info srch_inf;
313};
314
315/*
316 * One of these for each file inode
317 */
318
319struct cifsInodeInfo {
320 struct list_head lockList;
321 /* BB add in lists for dirty pages - i.e. write caching info for oplock */
322 struct list_head openFileList;
323 int write_behind_rc;
324 __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */
325 atomic_t inUse; /* num concurrent users (local openers cifs) of file*/
326 unsigned long time; /* jiffies of last update/check of inode */
327 unsigned clientCanCacheRead:1; /* read oplock */
328 unsigned clientCanCacheAll:1; /* read and writebehind oplock */
329 unsigned oplockPending:1;
330 struct inode vfs_inode;
331};
332
333static inline struct cifsInodeInfo *
334CIFS_I(struct inode *inode)
335{
336 return container_of(inode, struct cifsInodeInfo, vfs_inode);
337}
338
339static inline struct cifs_sb_info *
340CIFS_SB(struct super_block *sb)
341{
342 return sb->s_fs_info;
343}
344
ab2f218f 345static inline char CIFS_DIR_SEP(const struct cifs_sb_info *cifs_sb)
ac67055e
JA
346{
347 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
348 return '/';
349 else
350 return '\\';
351}
1da177e4 352
a4544347
SF
353#ifdef CONFIG_CIFS_STATS
354#define cifs_stats_inc atomic_inc
355
356static inline void cifs_stats_bytes_written(struct cifsTconInfo *tcon,
357 unsigned int bytes)
358{
359 if (bytes) {
360 spin_lock(&tcon->stat_lock);
361 tcon->bytes_written += bytes;
362 spin_unlock(&tcon->stat_lock);
363 }
364}
365
366static inline void cifs_stats_bytes_read(struct cifsTconInfo *tcon,
367 unsigned int bytes)
368{
369 spin_lock(&tcon->stat_lock);
370 tcon->bytes_read += bytes;
371 spin_unlock(&tcon->stat_lock);
372}
373#else
374
375#define cifs_stats_inc(field) do {} while(0)
376#define cifs_stats_bytes_written(tcon, bytes) do {} while(0)
377#define cifs_stats_bytes_read(tcon, bytes) do {} while(0)
378
379#endif
380
1da177e4
LT
381/* one of these for every pending CIFS request to the server */
382struct mid_q_entry {
383 struct list_head qhead; /* mids waiting on reply from this server */
384 __u16 mid; /* multiplex id */
385 __u16 pid; /* process id */
386 __u32 sequence_number; /* for CIFS signing */
1047abc1
SF
387 unsigned long when_alloc; /* when mid was created */
388#ifdef CONFIG_CIFS_STATS2
389 unsigned long when_sent; /* time when smb send finished */
390 unsigned long when_received; /* when demux complete (taken off wire) */
391#endif
1da177e4
LT
392 struct cifsSesInfo *ses; /* smb was sent to this server */
393 struct task_struct *tsk; /* task waiting for response */
394 struct smb_hdr *resp_buf; /* response buffer */
395 int midState; /* wish this were enum but can not pass to wait_event */
c81156dd 396 __u8 command; /* smb command code */
c81156dd 397 unsigned largeBuf:1; /* if valid response, is pointer to large buf */
3979877e
SF
398 unsigned multiRsp:1; /* multiple trans2 responses for one request */
399 unsigned multiEnd:1; /* both received */
1da177e4
LT
400};
401
402struct oplock_q_entry {
403 struct list_head qhead;
404 struct inode * pinode;
405 struct cifsTconInfo * tcon;
406 __u16 netfid;
407};
408
ff5dbd9e
SF
409/* for pending dnotify requests */
410struct dir_notify_req {
411 struct list_head lhead;
412 __le16 Pid;
413 __le16 PidHigh;
414 __u16 Mid;
415 __u16 Tid;
416 __u16 Uid;
417 __u16 netfid;
418 __u32 filter; /* CompletionFilter (for multishot) */
419 int multishot;
e22cb8bc 420 struct file * pfile;
ff5dbd9e
SF
421};
422
1da177e4
LT
423#define MID_FREE 0
424#define MID_REQUEST_ALLOCATED 1
425#define MID_REQUEST_SUBMITTED 2
426#define MID_RESPONSE_RECEIVED 4
427#define MID_RETRY_NEEDED 8 /* session closed while this request out */
428#define MID_NO_RESP_NEEDED 0x10
ec637e3f
SF
429
430/* Types of response buffer returned from SendReceive2 */
431#define CIFS_NO_BUFFER 0 /* Response buffer not returned */
432#define CIFS_SMALL_BUFFER 1
433#define CIFS_LARGE_BUFFER 2
434#define CIFS_IOVEC 4 /* array of response buffers */
1da177e4 435
3979877e
SF
436/* Security Flags: indicate type of session setup needed */
437#define CIFSSEC_MAY_SIGN 0x00001
438#define CIFSSEC_MAY_NTLM 0x00002
439#define CIFSSEC_MAY_NTLMV2 0x00004
440#define CIFSSEC_MAY_KRB5 0x00008
441#ifdef CONFIG_CIFS_WEAK_PW_HASH
442#define CIFSSEC_MAY_LANMAN 0x00010
443#define CIFSSEC_MAY_PLNTXT 0x00020
444#endif /* weak passwords */
445#define CIFSSEC_MAY_SEAL 0x00040 /* not supported yet */
446
447#define CIFSSEC_MUST_SIGN 0x01001
448/* note that only one of the following can be set so the
449result of setting MUST flags more than once will be to
450require use of the stronger protocol */
451#define CIFSSEC_MUST_NTLM 0x02002
452#define CIFSSEC_MUST_NTLMV2 0x04004
453#define CIFSSEC_MUST_KRB5 0x08008
454#ifdef CONFIG_CIFS_WEAK_PW_HASH
455#define CIFSSEC_MUST_LANMAN 0x10010
456#define CIFSSEC_MUST_PLNTXT 0x20020
457#define CIFSSEC_MASK 0x37037 /* current flags supported if weak */
458#else
459#define CIFSSEC_MASK 0x07007 /* flags supported if no weak config */
460#endif /* WEAK_PW_HASH */
461#define CIFSSEC_MUST_SEAL 0x40040 /* not supported yet */
462
463#define CIFSSEC_DEF CIFSSEC_MAY_SIGN | CIFSSEC_MAY_NTLM | CIFSSEC_MAY_NTLMV2
464#define CIFSSEC_MAX CIFSSEC_MUST_SIGN | CIFSSEC_MUST_NTLMV2
1da177e4
LT
465/*
466 *****************************************************************
467 * All constants go here
468 *****************************************************************
469 */
470
471#define UID_HASH (16)
472
473/*
474 * Note that ONE module should define _DECLARE_GLOBALS_HERE to cause the
475 * following to be declared.
476 */
477
478/****************************************************************************
479 * Locking notes. All updates to global variables and lists should be
480 * protected by spinlocks or semaphores.
481 *
482 * Spinlocks
483 * ---------
484 * GlobalMid_Lock protects:
485 * list operations on pending_mid_q and oplockQ
486 * updates to XID counters, multiplex id and SMB sequence numbers
487 * GlobalSMBSesLock protects:
488 * list operations on tcp and SMB session lists and tCon lists
489 * f_owner.lock protects certain per file struct operations
490 * mapping->page_lock protects certain per page operations
491 *
492 * Semaphores
493 * ----------
494 * sesSem operations on smb session
495 * tconSem operations on tree connection
496 * fh_sem file handle reconnection operations
497 *
498 ****************************************************************************/
499
500#ifdef DECLARE_GLOBALS_HERE
501#define GLOBAL_EXTERN
502#else
503#define GLOBAL_EXTERN extern
504#endif
505
506/*
507 * The list of servers that did not respond with NT LM 0.12.
508 * This list helps improve performance and eliminate the messages indicating
509 * that we had a communications error talking to the server in this list.
510 */
511GLOBAL_EXTERN struct servers_not_supported *NotSuppList; /*@z4a */
512
513/*
514 * The following is a hash table of all the users we know about.
515 */
516GLOBAL_EXTERN struct smbUidInfo *GlobalUidList[UID_HASH];
517
518GLOBAL_EXTERN struct list_head GlobalServerList; /* BB not implemented yet */
519GLOBAL_EXTERN struct list_head GlobalSMBSessionList;
520GLOBAL_EXTERN struct list_head GlobalTreeConnectionList;
521GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */
522
523GLOBAL_EXTERN struct list_head GlobalOplock_Q;
524
ff5dbd9e 525GLOBAL_EXTERN struct list_head GlobalDnotifyReqList; /* Outstanding dir notify requests */
254e55ed 526GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q;/* DirNotify response queue */
ff5dbd9e 527
1da177e4
LT
528/*
529 * Global transaction id (XID) information
530 */
531GLOBAL_EXTERN unsigned int GlobalCurrentXid; /* protected by GlobalMid_Sem */
254e55ed 532GLOBAL_EXTERN unsigned int GlobalTotalActiveXid; /* prot by GlobalMid_Sem */
1da177e4 533GLOBAL_EXTERN unsigned int GlobalMaxActiveXid; /* prot by GlobalMid_Sem */
254e55ed
SF
534GLOBAL_EXTERN spinlock_t GlobalMid_Lock; /* protects above & list operations */
535 /* on midQ entries */
1da177e4
LT
536GLOBAL_EXTERN char Local_System_Name[15];
537
538/*
539 * Global counters, updated atomically
540 */
541GLOBAL_EXTERN atomic_t sesInfoAllocCount;
542GLOBAL_EXTERN atomic_t tconInfoAllocCount;
543GLOBAL_EXTERN atomic_t tcpSesAllocCount;
544GLOBAL_EXTERN atomic_t tcpSesReconnectCount;
545GLOBAL_EXTERN atomic_t tconInfoReconnectCount;
546
547/* Various Debug counters to remove someday (BB) */
4498eed5
SF
548GLOBAL_EXTERN atomic_t bufAllocCount; /* current number allocated */
549#ifdef CONFIG_CIFS_STATS2
550GLOBAL_EXTERN atomic_t totBufAllocCount; /* total allocated over all time */
551GLOBAL_EXTERN atomic_t totSmBufAllocCount;
552#endif
553GLOBAL_EXTERN atomic_t smBufAllocCount;
1da177e4
LT
554GLOBAL_EXTERN atomic_t midCount;
555
556/* Misc globals */
254e55ed 557GLOBAL_EXTERN unsigned int multiuser_mount; /* if enabled allows new sessions
1da177e4
LT
558 to be established on existing mount if we
559 have the uid/password or Kerberos credential
560 or equivalent for current user */
561GLOBAL_EXTERN unsigned int oplockEnabled;
562GLOBAL_EXTERN unsigned int experimEnabled;
563GLOBAL_EXTERN unsigned int lookupCacheEnabled;
564GLOBAL_EXTERN unsigned int extended_security; /* if on, session setup sent
565 with more secure ntlmssp2 challenge/resp */
1da177e4 566GLOBAL_EXTERN unsigned int sign_CIFS_PDUs; /* enable smb packet signing */
3979877e 567GLOBAL_EXTERN unsigned int secFlags;
1da177e4
LT
568GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
569GLOBAL_EXTERN unsigned int CIFSMaxBufSize; /* max size not including hdr */
570GLOBAL_EXTERN unsigned int cifs_min_rcv; /* min size of big ntwrk buf pool */
571GLOBAL_EXTERN unsigned int cifs_min_small; /* min size of small buf pool */
572GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/
573